Use of lift bag when bc fails

[TMHeimer]

FWIW, I take a spool with the depth I am diving or want to shoot a bag from. Usually, my max is about 100'. I deploy 0 ft before I add air. Loose line is easy to get entangled in so I keep it as short as humanly possible. Shoot the bag and let go of the spool. Watch the spool gently fall back down. Easy peasy.

Not crazy about letting go of the spool (or anything) with the viz we may have.

 

[shoredivr]

Nasty comments kept me from sb. But it is part of the mentality here. DM and instructor just means you know how to demo skills on the bottom of a pool or lake, not dealing with double steels at midwater. I brought this up about putting my 2 steel tanks together to practice skills. My GUE instructor said noooo .. not safe. But the many technical divers I met said it is perfectly safe with a lift bag. So I posed the same question here 3 years ago, and getting a similar response. It is only a mental game for me, to see who is right and wrong. As it seems to be something people deal with differently. I have read it is possible to paddle and support a heavy steel rig. But there are situations where you should prethink? Don’t you think? I dive only singles- but have seen alot of double steels on wetsuit. But all on hard bottom. Yes I have shot smb from depth, from stops, and from bottom. But not with a fully loaded doubles, decos, etc that you folks do. Would consider doubles, but to me drysuit is just another mental load I can do without.

If no drysuit, get a redundant bladder wing if you are diving heavy steels and a wetsuit.

 

[Centrals]

That was the whole point of the discussion, the ease and safety of managing a failed wing with a very negative rig that is dragging you faster than you can swim upward. Besides, the first time one deploy a smb, it is good to understand the physics, pull, and difficulty positioning oneself in a current. It is easier to untangle from a mess, or deal with a stuck reel when you are safely anchored with your bc emtied in the bottom of the sea or pool. First time deployment of a new reel should be in a controlled environment.

If you need a hard bottom to practice shooting a bag then you are NOT ready to use the bag as a emergency buoyancy control device.
BTW, not all smb are suitable to be used as buoyancy control device.

 

[rsingler]

Per the OP, the scenario we are debating here is wetsuit and steel doubles.

Why not make the ascent much less stressful and compute how much weight you need to ditch to be able to swim this rig up? With a PARTIAL weight ditching, there is probably some depth short of the surface at which you become neutrally buoyant, making the final surface ascent much less of a big deal.

Then, whatever DSMB you shoot to use as supplemental lift might be either unnecessary or relatively small.

See: Buoyancy, Balanced Rigs, Failures and Ditching – a comprehensive tool
Find out how negative you might be with your proposed rig, and what lead you need to ditch to make it recoverable BEFORE you have to resort to redundant lift. There are just not that many rig combinations that are irrecoverably negative with ditchable weight.

 

[fisherdvm]

If you need a hard bottom to practice shooting a bag then you are NOT ready to use the bag as a emergency buoyancy control device.
BTW, not all smb are suitable to be used as buoyancy control device.

I think we have to agree to disagree. Many divers if not most do not have the skills to deploy ANYthing at ANY depth midwater. But emergency situation can happen at ANY time when they are lobstering solo. I will still tell them to deploy their SMB with what ever reel or spool they have sitting on the bottom heavily negative with the bc deflated than risk a neutrally balanced midwater diver at 15 ft monkeying around with a tangled mess while propellers are overhead. This scenario occurs everyday in our country- less than qualified divers chasing lobsters down to 300 psi then have to surface with an smb. Hard bottom is where THEY need to deploy! Think of the skills it needs to find that reel, smb, tangled in a lobster hotel, tickle stick, 3 ft lionfish spear, measuring device, camera, light, lobster snare... all clipped to the same damn bcd! And some of us still BLOW our smb, as it is the only way to do it for some model. Not all of us have DIR approved everything and dive the GUE way, e

 

[fisherdvm]

If you need a hard bottom to practice shooting a bag then you are NOT ready to use the bag as a emergency buoyancy control device.
BTW, not all smb are suitable to be used as buoyancy control device.

Agree. But we should know how to use all tools in the bag. Besides, lead is now very expensive, and ordering a set of weight inserts takes at least 2 business days with Amazon Prime!

 

[The Chairman]

Which sausages do you use @The Chairman ? Do some catch?

None catch, but not all have them. I use a Halcyon. Expensive, but worth it.

Why not make the ascent much less stressful and compute how much weight you need to ditch to be able to swim this rig up?

With Double steels and a wetsuit, you probably don't have any weight to drop. Maybe in a 7mm. I don't need weights on a set of lp85s and a drysuit. Dive Rite makes some awesome double bladder wings.

 

[AfterDark]

I've never had a BC failure but I've drilled for one in deep water. Dropping all weight is a no/go if properly weighted one should have the option of dropping some weight all or nothing is a hold over from the old days, things have changed. When I dropped 4lbs 2lbs at a time, my descent stopped, I became neutral and had plenty of time to deploy my lift bag. Which I use to make a controlled ascent complete with safety stop.

How it'll work real world in an emergency is still unknown to me, and here's to it staying that way!

 

[aquacat8]

There are definitely skills involved. I learned that the hard way recently when I screwed up royally sending a brand new 6 foot Hog DSMB up from 30 feet after two dives at West Palm Beach and a morning dive at Blueheron bridge. I had done this successfully before with a 4 foot DSMB, but I lost that SMB at on a night dive at BHB practicing clipping/unclipping.

I complicated my idiocy by switching from a spool to a plastic ratcheting reel I hadn’t used in over a year (but that I had used successfully with the small dsmb).
I also was trying to inflate the new DSMB with a second stage, as I had orally inflated on the previous dive and it hadn’t filled enough. It didn’t work very well as I wasn’t holding it exactly level and bubbles were missing the opening, so it took too long. Then when I released it, I forgot to hold down the lever on the ratcheting reel, somehow expecting it to unspool like a spool, and as I was holding the reel, I went straight up with it before I knew it.

I finally let go, but now I was about 10 feet under it and it was on the surface. Stupidly stubborn about my investment, I swam up and grabbed it, and descended for a long safety stop.

All in all I was an idiot in numerous ways and I’m heartily ashamed.

 

[The Chairman]

All in all I was an idiot in numerous ways and I’m heartily ashamed.

This stuff is easy to do ONCE you know the tricks. Until then, it's all trial and error.